1. Field of the Invention
The present invention relates to a center mounting type air conditioner for a vehicle, and more particularly, to a center mounting type air conditioner for a vehicle, which can bypass some of air sucked from an intake duct through at least one dead space located between a scroll case and an air conditioning case and blow it toward a wheel of a dual blower wheel to which a motor is connected, thereby reducing size and noise of a blower, and enhancing installation efficiency and reducing an installation space of the air conditioner mounted in the vehicle since the front side of the air conditioner has a vertical plane.
2. Background Art
To use the indoor space of a vehicle efficiently, a necessity of a compact type and small-sized air conditioner for the vehicle is being increased. According to such necessity, a semi-center type air conditioner including an evaporator unit and a heater unit, which are integrated with each other, has been generally used.
However, recently, development of a center-mounting type air conditioner including a blast unit, an evaporator unit and a heater unit, which are integrated together, is being increased. FIG. 1 shows a prior art center mounting type air conditioner for a vehicle.
In FIG. 1, the center mounting type air conditioner for the vehicle includes: a blower 10; an air conditioning case 40 having an inlet connected to the blower 10 and an outlet, the outlet having a number of air vents 42 each of which is adjustable in an opening; an evaporator 20 and a heater core 30 embedded in the air conditioning case 40; and at least one temperature-adjustable door 44 for adjusting the opening of a cool air passageway P1 and a hot air passageway P2 of the air conditioning case 40.
The center-mounting type air conditioner for the vehicle is generally classified into three kinds according to a structure of the blower 10 for sucking air and blowing the air toward the air conditioning case 40.
First, one of the three kinds of the blowers has a structure to suck air bi-directionally, namely, in right and left directions. As shown in FIG. 2, the blower 10a includes two scroll cases 11a and 11a, two intake ducts 12a and 12a respectively connected to the outer circumference of each scroll case 11a for sucking the indoor air or the outdoor air; a motor 13a mounted between the two scroll cases 11a and 11a; and two blower wheels 14a and 14a respectively connected to shafts protruding outwardly from both sides of the motor 13a, each blower wheel 14a being mounted inside each scroll case 11a. 
Thereby, when the opening of each intake duct 12a is adjusted by a door (not shown), the indoor air or the outdoor air is sucked toward both sides of the blower 10a, and then, blown to the inside of the air conditioning case 40 through each scroll case 11a. 
The prior art center mounting type air conditioner to which the blower 10a of FIG. 2 is applied has an advantage in that it can supply sufficient air volume and reduce noise, but has a disadvantage in that it is difficult to achieve a compact type or small-size air conditioner for a vehicle since the blower 10a has two air intake structures located at right and left sides thereof.
Furthermore, the prior art center mounting type air conditioner to which the blower 10a of FIG. 2 is applied has another disadvantage in that it cannot provide good installation efficiency and occupies a wide installation space when it is installed in rear of a dash panel of the vehicle since the front side of the air conditioner, namely, the front side of the blower 10a, does not have a vertical plane and the upper portion thereof is projected forwardly.
FIG. 3 shows another blower lob having a structure to suck air bi-directionally, namely, in right and left directions.
The blower 10b includes a scroll case 11b, an intake duct 12b connected to the scroll case 11b for sucking the indoor air or the outdoor air, a dual blower wheel 14b rotatably mounted inside the scroll case 11b, and a motor 13b for rotating the dual blower wheel 14b. 
As shown in FIG. 4, the dual blower wheel 14b has two wheels 15b and 16b disposed on both sides of a hub plate 17b to which the motor 13b is connected.
As described in the above, the blower 10b of FIG. 3 has a size smaller than the blower 10a of FIG. 2 since the blower 10b of FIG. 3 has one scroll case 11b, and provides sufficient air volume since it sucks and blows air bi-directionally.
However, the blower 10b of FIG. 3 has a disadvantage in that it generates serious noise due to an interference caused between a flow of air sucked toward the wheel 16b of the motor 13b and a flow of air blown out from the wheels 15b and 16b as shown in FIG. 4.
Meanwhile, the other blower (not shown), which has one blower wheel, may be applied to the air conditioner for the vehicle. The blower having one blower wheel can reduce noise sufficiently, but not provide proper size and air volume.